Sydney vs. Perth

I've heard great things about both of these cities and I'll be spending two months traveling by train, bus and motorcycle across the country to see as much of Australia as I can; I've heard that Sydney and Perth are both great and would love to know what other InterNations members who have lived in or visited both think of Sydney and Perth.

I know that it will depend greatly on my personal preferences, but I would love to hear your insights as well. Any opinion is welcome in helping me decide where to live!